When we transitioned Melody from breast milk to formula, I had to find a way to better prep bottles so that I was not making one bottle at a time.  I tried a couple of methods, but in the end, I found a solution that works great for us right now.  Currently Melody is taking 5 ounce bottles 6 times a day.  As her bottles get bigger, my method may not be the most efficient, but it works great now.